Community and Migrant Health Centers (C/MHCs), funded by the Health Resources and Services Administration (HRSA), and are an important source of health care services for residents of medically underserved communities. The centers' ability to provide access to good quality services for otherwise underserved populations depends in part on the extent to which they are able to attract and, then, retain competent health care professionals. Turnover disrupts patient-physician relationships; and while some turnover is to be expected, an excessive amount can undermine patient confidence in the center and even in the ability of medical care to produce desired outcomes. In recent years, many centers have had difficulty retaining clinical staff, especially physicians. This is a study aimed at discovering 1. the extent of stability among C/MHC physician staffs; 2. not only whether physicians leave centers, but when; 3. the factors that affect the extent to which physicians voluntarily remain with the Health Centers for an extended period, emphasizing a. differences between NHSC physicians and others; b. organizational factors under the control of the C/MHC The study will be conducted in 3 phases: In Phase 1, the primary purpose is to examine stability in the physician staffing of C/MHCs. Here, the Center is the principal unit of analysis, although we will also plot survival curves and hazard profiles for physicians in the centers. In Phase 2, the focus is on the decision-making of individual physicians on the issue of whether to stay at the center or to leave. Samples of center physicians will be surveyed and multivariate analyses will be used to explain the survival and hazard curves. In phase 3, we will do in-depth case studies in 8 Centers to learn in three-dimensional detail of the extent to which professional life in the centers affects physician willingness to remain.